JP5754835B2 - Electric gripping member - Google Patents

Description

The present invention relates to a member that grips an object by opening and closing a finger-shaped member, and particularly relates to a gripping member suitable for an electric prosthesis.

Patent Document 1 describes a linear actuator and an electric prosthetic hand that opens and closes fingers by a link mechanism. Patent Document 2 describes an electric prosthetic hand that can be bent and extended by a composite four-joint link and a planetary gear device so as to follow a shape of the gripping body so that a reliable gripping posture can be achieved. Non-Patent Document 1 describes a myoelectric prosthetic hand that uses one myoelectric sensor and bends one polypropylene sheet so that the thumb finger and the second and third fingers oppose each other and perform a three-point knob. .

Japanese Patent Laid-Open No. 11-56885 JP 2004-41279 A

Takanori Higashihara “Development of Simple Myoelectric Prosthesis” The 16th Annual Meeting of the Japanese Prosthetics and Orthotics Association, p104-105, 2009

In the electric prosthesis of Patent Document 1, three types of large link members are connected to each other so as to freely rotate to form a link mechanism. Although a specific description of this link mechanism is poor, it can be seen from FIG. 1 that the link members are connected by a bearing mechanism. Such a link configuration is suitable for a large machine or the like, but it is difficult to reduce the size and weight. In particular, small prostheses for women and children are desired to be small and light. The electric prosthesis of Patent Document 1 is aimed at miniaturization, but has a complicated structure using a planetary gear device or the like. Therefore, the cost must be high.

On the other hand, the invention of Non-Patent Document 1 shows the possibility of reducing the size and weight, and aims to put the myoelectric prosthetic hand at a low price into practical use. However, for a myoelectric prosthesis having the same appearance as a decorative prosthesis, a reduction in size and weight is expected. Moreover, if not only the operation of gripping an object but also a state where the palm is flattened, a myoelectric prosthesis that is easier to use can be realized. An object of the present invention is to provide a myoelectric prosthesis that has a simple structure and can be reduced in size and weight.

In order to solve the above-described object, an electric gripping member of the present invention includes a finger member support portion, a slide member that reciprocates with respect to the finger member support portion, an electric motor that drives the slide member, and a first finger member And a second finger member, and an electric gripping member that opens and closes the first finger member and the second finger member by an electric motor, wherein the first finger member and the second finger member are each attached to a slide member. It has a finger member support part connection part attached to a member connection part and a finger member support part,
The first finger member, the slide member connecting portion and the finger member supporting portion connecting portion are formed by bending a single plate-like member,
The second finger member, the slide member connecting portion, and the finger member supporting portion connecting portion are also formed by bending a single plate-like member.
The first finger member and the second finger member may be formed by bending a single plate-like member, or formed by bending different plate-like members, and the slide member connecting portions rotate with each other. It may be connected as possible.

The electric gripping member of the present invention has a simple structure in which a finger member and main members for opening and closing are formed by bending a plate-like member. Therefore, it can be made small and light, and the cost can be kept low.

It is a front view which shows the outline | summary of an electric holding member. It is the same side view. It is a graph which shows the open / close control by a myoelectric sensor. It is a front view which shows the outline | summary of the modification of an electrically-driven holding member.

An embodiment for carrying out the present invention will be described with reference to the drawings. FIG. 1 is a front view showing an outline of the electric gripping member, and FIG. 2 is a side view thereof.

The electric gripping member 1 includes a finger member support portion 2, a slide member 3 that reciprocates relative to the finger member support portion 2, an electric motor 4 that drives the slide member 3, a first finger member 5, and a second member. And a finger member 6. In this example, a DC coreless motor manufactured by Maxon Corporation was used as the electric motor.

The finger member support 2 is a member formed by bending a metal plate or the like. It has a plate-shaped central surface 2a, and side plates 2b and 2c are provided at both ends at a predetermined angle. In FIG. 1, the side plates 2b and 2c are substantially perpendicular to the central portion 2a. However, when applied to an electric prosthetic hand, the shape of the human hand may be faithfully reproduced by bending it obliquely. The front end portions of the side plates 2b and 2c are portions to be connected to a finger member to be described later, and in particular, the back side of the hand of the finger member is attached.

A hole is made in the central portion of the finger member supporting portion 2, and a rotating shaft 7 connected to the electric motor 4 is passed through. The slide member 3 is provided to face the central surface 2a of the finger member support 2. Here, the slide member 3 is formed of a feed screw. A male screw is provided near the tip of the rotating shaft 7, and the feed screw 3 is attached to the male screw. When the rotating shaft 7 is rotated by the electric motor 4, the feed screw 3 moves along the length direction of the rotating shaft 7 and acts as a slide member.

The first finger member 5 corresponds to a thumb (thumb) and is usually formed with one finger. On the other hand, the number of fingers of the second finger member 6 may be one or more. When used as a robot hand, the second finger member 6 may be a single finger. Even when used as a prosthetic hand, one finger may be used, but two fingers corresponding to the second and third fingers may be provided.

The first finger member 5 and the second finger member 6 have slide member connection portions 8a and 8b attached to the slide member 3 and finger member support portion connection portions 9a and 9b attached to the finger member support portion 2, respectively. In this invention, the 1st finger member 5, the slide member connection part 8a, and the finger member support part connection part 9a are formed by the bending of one plate-shaped member. Similarly, the second finger member 6, the slide member connecting portion 8b, and the finger member supporting portion connecting portion 9c are formed by bending a single plate-like member. As the plate-like member, a plate material having a predetermined strength that can be easily cut and bent can be used. For example, a polypropylene sheet having a thickness of 2 mm can be selected as a lightweight and safe material.

The outside of the finger members 5 and 6, that is, the upper side and the palm side surfaces are formed by plate-like members. And about two reinforcements 10 are provided inside. Here, a cylindrical hard plastic is attached between plate members by bolts so that the shape of the finger is maintained.

Finger member support portion connection portions 9a and 9b are formed at one end of the finger members 5 and 6. And this connection part is bending line 11a, 11b. The bending angle of the bending line is freely changed. Slide member connecting portions 8a and 8b are provided at the other end portions of the finger members 5 and 6, and the bending angle is freely changed also in the folding lines 12a and 12b formed therebetween. Further, in the slide member connecting portions 8a and 8b, bending lines 13a and 13b whose bending angles are freely changed are also formed near the portion attached to the slide member 3.

Therefore, the finger member support 2 and the slide member 3 are linked via the three folding lines 11, 12, and 13. The finger members 5, 6, the slide member connection portions 8 a, 8 b and the finger member support portion connection portions 9 a, 9 b constitute a link mechanism, and the angle of the finger members 5, 6 with respect to the finger member support portion 2 by the movement of the slide member 3 Changes. When the slide member 3 moves away from the finger member support portion 2, the finger members 5 and 6 try to open, and when approaching, the finger members 5 and 6 try to close.

As described above, among the main members for functioning as an electric gripping member, the finger member, the slide member connecting portion, and the finger member supporting portion connecting portion are configured by bending a single plate-like member, and the finger member supporting portion is also It can be formed by bending a metal plate or the like. In particular, in the example of FIG. 1, the first finger member and the second finger member can be formed from a single plate-like member, the number of parts is extremely small, and processing and assembly are easy. Therefore, it can be made small, light and low cost.

In particular, when a synthetic resin plate such as a polypropylene sheet is used as the finger member, it is easy to cut out and bend the plate. Even complicated shapes can be cut out freely, and the shape of each user's finger can be faithfully reproduced. By appropriately selecting the position and direction of the fold line, it is possible to realize a finger opening / closing motion that can be properly grasped and that looks natural.

A hand-shaped glove can be put on the electric gripping member to make a myoelectric prosthesis. As a glove for a decorative prosthetic hand, one that faithfully reproduces the appearance and touch of a human hand is widely used. Since the electric gripping member of the present invention can be configured to be small and light, it can be housed in a socket or glove for a decorative prosthesis. Therefore, it is hard to be seen as an electric prosthesis and has a natural appearance.

The electric motor 4 is controlled by the computer 14. Here, PIC16F873 was used as the microcomputer. By using a computer, the type and number of sensors, the degree of freedom, the operation method, and the like can be changed. While using the same control circuit, an operation method according to the remaining ability of the user can be selected. It is possible to experience a plurality of operation methods and to select a suitable one for the user, and to change to a new operation method as the operation progresses through training.

Here, one Otto Bock myoelectric sensor is used. The myoelectric sensor detects a nerve signal that controls the muscle and outputs it as an electrical signal. Otbock's myoelectric sensor operates with a single 6V power supply, rectifies and smoothes the myoelectric signal as an output signal, and sends it directly to the computer.

It is a graph which shows the opening / closing control of the finger member by a myoelectric sensor. In order to control opening and closing of the finger member, a first boundary value and a second boundary value lower than the first boundary value are determined. When the output signal V (t) of the myoelectric sensor is higher than the first boundary value, an operation of opening the finger member is performed, and an operation of closing the finger member between the first boundary value and the second boundary value is performed. When it is lower, stop is instructed. Furthermore, the operation direction of the finger member is determined based on the determination of the direction of change of the signal (identification of increase / decrease) by comparison with the previous output signal V (t−1). Further, a delay time of 10 msec is provided from when the output signal V (t) exceeds the boundary value until the operation starts.

Currently, myoelectric sensors are expensive, so if a plurality of sensors are used, the entire apparatus becomes expensive. As shown in FIG. 3, by controlling the operation in both the opening and closing directions with a single myoelectric sensor, the cost can be reduced even in the control portion.

An example in which the above-described myoelectric sensor and computer control device are applied to a user will be described. This user is a 38-year-old woman who is left-handed, and has lost her right hand because of a work accident when she was 20 years old. Cut at 12cm from the elbow.

Right elbow automatic extension 0 °, flexion 100 °. The output signal of the extensor group was seen when the flexor contracted, and the extensor and flexor could not be distinguished sufficiently. Therefore, based on the control method as shown in FIG. 3, the finger member in both the opening and closing directions is controlled by one myoelectric sensor.

First, without using a myoelectric prosthetic hand, training was performed for about 30 minutes using a personal computer to learn the operation method, and then the myoelectric prosthetic hand was actually worn to confirm operability. Immediately after the operation, the finger member could be opened and closed without causing any malfunction regardless of the position of the arm.

As described above, the myoelectric prosthesis is easy to operate and can be learned in a short time, so that it can be used immediately after creation. You can grasp and release objects at your own will.

Furthermore, a modified example of the present invention will be described. FIG. 4 is a front view showing an outline of a modified example of the electric gripping member, and the finger member support portion and the slide member are different from the above-described example. In this example, the slide member is divided into two partial members, and are attached so as to be rotatable around the rotation shaft 7. Further, the finger member support portion is also divided into two members and can be rotated around the rotation shaft 7. Therefore, the 1st finger member and the 2nd finger member can rotate mutually.

Here, the second finger member corresponding to the second finger (index finger) and the third finger (middle finger) of the hand is fixed, and the first finger member corresponding to the thumb is rotatable. When the object is not gripped, the first finger member can be rotated with the finger members open so that the first finger member is substantially flush with the second and third fingers. This rotation can be done with the other normal hand. As a result, a state in which the hand is opened can be realized. When a thin sheet such as paper is pressed with the palm, the first finger member does not interfere.

1. 1. Electric gripping member 2. Finger member support part 3. Slide member Electric motor5. First finger member 6. Second finger member 7. Rotation axis 8. 8. Slide member connection part Finger member support part connection part 10. Reinforcing material11. Bending line 12. Bending line 13. Bending line 14. Computer 15. Myoelectric sensor

Claims (3)

A finger member supporting portion; a slide member that reciprocates with respect to the finger member supporting portion; an electric motor that drives the sliding member; a first finger member; and a second finger member. An electric gripping member for opening and closing the member and the second finger member,
A slide member connection portion attached to the slide member and a finger member support portion connection portion attached to the finger member support portion are provided at ends of the first finger member and the second finger member , respectively .
The first finger member, the slide member connecting portion, and the finger member supporting portion connecting portion are formed by bending a single synthetic resin plate member,
The second finger member and the slide member connecting portion and the finger member supporting portion connecting portion are also formed by bending a single synthetic resin plate member,
The first finger member and the second finger member have an outer portion formed by a plate-like member and a reinforcing material provided inside the plate-like member to maintain the shape of the finger,
In the first finger member and the second finger member , a fold line formed at the finger member support portion connecting portion that changes a fold angle, a fold line formed at the slide member connecting portion that changes a fold angle , and the first finger An electric gripping member for an electric prosthetic hand provided with a fold line formed between the member or the second finger member and the slide member connecting portion and having a bending angle changed . The electric gripping member for an electric prosthetic hand according to claim 1, wherein the first finger member and the second finger member are formed by bending a single plate-like member. The first finger member and the second finger member are formed by bending different plate-like members, and the slide member connecting portion of the first finger member and the slide of the second finger member are centered on the rotation shaft connected to the electric motor. The electric gripping member for an electric prosthetic hand according to claim 1, wherein the member connecting portions are connected to each other so as to be rotatable.

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